Udoekpo Imeobong U, Inyangudoh Akwaowo I, Awa-Arua Treasure A, Ogwo Ekeoma I, Offiong Nnanake-Abasi O, Inam Edu J, Halsall Crispin J
Department of Chemistry, University of Uyo, Uyo, Nigeria.
Centre for Energy and Environmental Sustainability Research (CEESR), University of Uyo, Uyo, Nigeria.
Toxicol Rep. 2024 Nov 30;13:101843. doi: 10.1016/j.toxrep.2024.101843. eCollection 2024 Dec.
The use of pesticides in commercial farms can lead to exposure among various vulnerable groups. This study assessed the distribution, human health risks, and origins of 13 targeted organochlorine pesticides (OCPs) in soil samples from commercial farms in Southern Nigeria. Following a questionnaire survey on pesticide usage, soil samples were subjected to Soxhlet extraction and analyzed using gas chromatography-mass spectrometry. Results indicated that 31.6 % of farmers did not use personal protective equipment, and only 37.6 % had received training on safe pesticide application. While pyrethroids and organophosphates were commonly used, organochlorines were rarely applied. The detected levels of OCPs in the agricultural zones ranged from below detection limit (BDL) to 18.35 ± 13.83 µg/kg and were generally within the minimum risk level (MRL), except for α-HCH and β-HCH in Oron and Etinan zones. The estimated non-carcinogenic risk s from detected OCPs were insignificant at the time of the study, as the calculated Hazard Indexes (HIs) and Hazard Quotients (HQs) for ingestion, dermal absorption, and inhalation were all less than 1, indicating generally low risks. The carcinogenic risk assessment showed that the Incremental Lifetime Cancer Risk (ILCR) values ranged from 10 to 10, indicating a very low to low risk level according to the classification by the United States Agency for Toxic Substances and Disease Registry (US ATSDR). Source apportionment suggested that most OCP congeners were of historical origin, with only a few indicating recent use. In conclusion, organochlorine pesticide residues in the studied farms posed minimal health risks, with most originating from historical rather than recent use.
商业农场中农药的使用可能导致各类弱势群体接触到农药。本研究评估了尼日利亚南部商业农场土壤样本中13种目标有机氯农药（OCPs）的分布、对人类健康的风险及来源。在对农药使用情况进行问卷调查后，对土壤样本进行索氏提取，并采用气相色谱 - 质谱联用仪进行分析。结果表明，31.6%的农民未使用个人防护装备，仅有37.6%的农民接受过安全施用农药的培训。虽然拟除虫菊酯类和有机磷类农药被普遍使用，但有机氯类农药很少施用。农业区中检测到的有机氯农药水平在低于检测限（BDL）至18.35±13.83µg/kg之间，除了奥龙和埃廷南区的α - 六氯环己烷和β - 六氯环己烷外，总体上处于最低风险水平（MRL）。在研究期间，检测到的有机氯农药估计的非致癌风险不显著，因为摄入、皮肤吸收和吸入的计算危害指数（HIs）和危害商（HQs）均小于1，表明总体风险较低。致癌风险评估显示，增量终生癌症风险（ILCR）值在10至10之间，根据美国有毒物质和疾病登记局（US ATSDR）的分类，表明风险水平非常低至低。源解析表明，大多数有机氯农药同系物源于历史遗留，只有少数表明是近期使用。总之，研究农场中的有机氯农药残留对健康造成的风险极小，大多数源于历史遗留而非近期使用。
